The Ministry of Finance estimated a 25 percent shortfall in collections against projections for March, with worse likely to come.
"The number that I'm providing now is very rough," said Finance Secretary May Bing Thursday.
"But when we looked at our figures for FY2020, our collection in March is way below budgeted/expected figures and may continue the trend in coming months."
She estimated the March tax shortfall at 25 percent.
"We do anticipate a decrease in collection as activities within the private sector are clearly challenged," Ms Bing added.